U.S. patent number 11,137,932 [Application Number 16/700,501] was granted by the patent office on 2021-10-05 for pad indication for device capability.
This patent grant is currently assigned to Western Digital Technologies, Inc.. The grantee listed for this patent is WESTERN DIGITAL TECHNOLOGIES, INC.. Invention is credited to Yoseph Pinto, Rotem Sela.
United States Patent |
11,137,932 |
Sela , et al. |
October 5, 2021 |
Pad indication for device capability
Abstract
Technology for detecting a capability set of a removable
integrated circuit card, such as a removable memory card, is
disclosed. The removable integrated circuit card has one or more
capability pads that indicate a capability set of the removable
integrated circuit card. The physical condition may be a physical
configuration of one or more capability pads, such as size or
location of a capability pad. A host device is able to determine
the capability set of the removable integrated circuit card based
on the physical condition of the capability pads. The host device
may determine the capability set without the card being powered on,
without reading a register in the card, or without exchanging
commands with the card.
Inventors: |
Sela; Rotem (Hod Hasharon,
IL), Pinto; Yoseph (Tel Aviv, IL) |
Applicant: |
Name |
City |
State |
Country |
Type |
WESTERN DIGITAL TECHNOLOGIES, INC. |
San Jose |
CA |
US |
|
|
Assignee: |
Western Digital Technologies,
Inc. (San Jose, CA)
|
Family
ID: |
1000005849195 |
Appl.
No.: |
16/700,501 |
Filed: |
December 2, 2019 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20210165595 A1 |
Jun 3, 2021 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G11C
13/004 (20130101); G06F 13/4063 (20130101); G06F
3/0658 (20130101); G06F 3/0653 (20130101); G06F
3/0673 (20130101); G06F 3/0617 (20130101) |
Current International
Class: |
G06F
3/06 (20060101); G11C 13/00 (20060101); G06F
13/40 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tsai; Henry
Assistant Examiner: Hassan; Aurangzeb
Attorney, Agent or Firm: Vierra Magen Marcus LLP
Claims
We claim:
1. An apparatus, comprising: a card connector configured to receive
a removable integrated circuit card having interface pads in a
first region and a plurality of target locations in a second
region, wherein the removable integrated circuit card comprises
zero or more capability pads at the plurality of target locations;
and one or more control circuits coupled to the card connector,
wherein the one or more control circuits are configured to:
determine a presence or an absence of a capability pad at each of
the plurality of target locations on the removable integrated
circuit card when the removable integrated circuit card is in the
card connector to determine a physical configuration of the zero or
more capability pads from a plurality of physical configurations,
wherein each of the plurality of physical configurations
corresponds to a different capability set of a plurality of
capability sets, determine which of the capability sets corresponds
to the determined physical configuration of the zero or more
capability pads, and operate the removable integrated circuit card
based on the determined capability set.
2. The apparatus of claim 1, wherein the one or more control
circuits are further configured to: provide a voltage to a first
end of a resistive element that has a second end connected to a
first target location of the plurality of target locations on the
removable integrated circuit card; and compare a magnitude of a
voltage at the first target location with a reference voltage in
order to determine the presence or absence of a capability pad at
the first target location.
3. The apparatus of claim 1, wherein the one or more control
circuits are further configured to: provide a voltage to a first
end of a resistive element that has a second end connected to a
first target location of the plurality of target locations on the
removable integrated circuit card; connect a second target location
of the plurality of target locations on the removable integrated
circuit card to ground while the voltage is provided to the first
end of the resistive element; and compare a magnitude of a voltage
at the first target location with a reference voltage in order to
determine the physical configuration of the zero or more capability
pads.
4. The apparatus of claim 1, wherein to determine the physical
configuration of the zero or more capability pads the one or more
control circuits are further configured to: provide a first voltage
to a first end of a first resistive element that has a second end
connected to a first target location of the plurality of target
locations on the removable integrated circuit card; provide a
second voltage to a first end of a second resistive element that
has a second end connected to a second target location of the
plurality of target locations on the removable integrated circuit
card, wherein the second voltage is provided to the first end of
the second resistive element while the first voltage is provided to
the first end of the first resistive element; compare a magnitude
of a third voltage at the first target location with a first
reference voltage; and compare a magnitude of a fourth voltage at
the second target location with a second reference voltage.
5. The apparatus of claim 1, further comprising: a first voltage
source configured to provide a first voltage to a first interface
pad of the interface pads; and a second voltage source configured
to provide a second voltage to a second interface pad of the
interface pads, the first voltage is greater than the second
voltage; wherein the one or more control circuits are further
configured to sense a voltage at each of the zero or more
capability pads when the first voltage is provided to the first
interface pad and the second voltage is provided to the second
interface pad.
6. The apparatus of claim 1, wherein the one or more control
circuits are further configured to: sense an absence of a
capability pad at any of the plurality of target locations on the
removable integrated circuit card; and determine the capability set
of the removable integrated circuit card based on the absence of a
capability pad at any of the plurality of target locations on the
removable integrated circuit card.
7. The apparatus of claim 1, wherein the one or more control
circuits are further configured to: determine presence or absence
of a capability pad at each of the plurality of target locations
while the removable integrated circuit card is powered off.
8. The apparatus of claim 1, wherein the one or more control
circuits are further configured to: sense at the plurality of
target locations on the card prior to the apparatus providing any
commands to the removable integrated circuit card.
9. The apparatus of claim 1, wherein: the removable integrated
circuit card comprises a removable memory card, the removable
memory card comprising non-volatile memory; and the capability set
comprises a voltage level at which the removable memory card is
capable of operating.
10. The apparatus of claim 1, wherein the one or more control
circuits configured to operate the removable integrated circuit
card based on the determined capability set comprises: the one or
more control circuits configured to use at least one of the
capability pads while operating the removable integrated circuit
card based on the determined capability set.
11. An apparatus, comprising: means for receiving a removable
memory card having interface pads in a first region and a plurality
of target locations in a second region, wherein the removable
memory card comprises zero or more capability pads at the plurality
of target locations; means for determining a presence or an absence
of a capability pad at each of the plurality of target locations on
the removable memory card when the removable memory card is being
received by the means for receiving a removable memory card; means
for determining a physical configuration of the zero or more
capability pads from a plurality of physical configurations based
on the presence or absence of a capability pad at each of the
plurality of target locations, wherein each of the plurality of
physical configurations corresponds to a different capability set
of a plurality of capability sets; means for determining which of
the capability sets corresponds to the determined physical
configuration of the zero or more capability pads; and means for
operating the removable memory card based on the determined
capability set.
12. The apparatus of claim 11, wherein the means for determining a
presence or an absence of a capability pad at each of the plurality
of target locations on the removable memory card is configured to:
provide a voltage to a first end of a resistive element in a host
device, wherein a second end of the resistive element is connected
to a first target location of a plurality of target locations; and
compare a magnitude of a voltage at the first target location with
a reference voltage.
13. The apparatus of claim 12, wherein the means for determining a
presence or an absence of a capability pad at each of the plurality
of target locations on the removable memory card is further
configured to: connect a second target location of the plurality of
target locations on the removable memory card to ground while the
voltage is provided to the first end of the resistive element.
14. A method comprising: receiving, in a card connector of a host
device, a removable memory card having interface pads in a first
region and a plurality of target locations in a second region,
wherein the removable memory card comprises zero or more capability
pads at the plurality of target locations; determining, by the host
device, a presence or an absence of a capability pad at each of the
plurality of target locations on the removable memory card when the
removable memory card is in the card connector; determining, by the
host device, a physical configuration of the zero or more
capability pads from a plurality of physical configurations based
on the presence or absence of a capability pad at each of the
plurality of target locations, wherein each of the plurality of
physical configurations corresponds to a different capability set
of a plurality of capability sets; determining, by the host device,
which of the capability sets corresponds to the determined physical
configuration of the zero or more capability pads; and operating,
by the host device, the removable memory card based on the
determined capability set.
15. The method of claim 14, wherein determining a presence or
absence of a capability pad at each of the plurality of target
locations on the removable memory card when the removable memory
card is in the card connector comprises: providing a first voltage
to a first end of a first resistive element in the host device,
wherein a second end of the first resistive element is connected to
a first target location on the removable memory card; and comparing
a magnitude of a voltage at the first target location with a first
reference voltage.
16. The method of claim 15, wherein determining a presence or
absence of a capability pad at each of the plurality of target
locations on the removable memory card when the removable memory
card is in the card connector further comprises: connecting a
second target location on the removable memory card to ground while
the first voltage is provided to the first end of the first
resistive element.
17. The method of claim 15, further comprising: providing a second
voltage to a first end of a second resistive element in the host
device, wherein a second end of the second resistive element is
connected to a second target location on the removable memory card
while the first voltage is provided to the first end of the first
resistive element; and comparing a magnitude of a voltage at the
second target location with a second reference voltage in order to
detect the physical configuration of the zero or more capability
pads of the removable memory card, wherein detecting the physical
configuration of the zero or more capability pads of the removable
memory card is further based on the comparison of the magnitude of
the voltage at the second target location with the second reference
voltage.
18. The method of claim 14, wherein: determining a presence or
absence of a capability pad at each of the plurality of target
locations on the removable memory card when the removable memory
card is in the card connector is performed while the removable
memory card is powered off.
19. The method of claim 14, wherein: determining a presence or
absence of a capability pad at each of the plurality of target
locations on the removable memory card when the removable memory
card is in the card connector is performed prior to the host device
exchanging information with the removable memory card as part of an
initialization process of the removable memory card.
20. The method of claim 14, wherein operating the removable memory
card based on the determined capability set comprises providing a
voltage to a power supply interface pad of the removable memory
card, wherein a magnitude of the voltage to the power supply
interface pad depends on the determined capability set of the
removable memory card.
Description
BACKGROUND
Removable integrated circuit cards, as the term is used herein, are
cards that contain one or more integrated circuits and that may be
repeatedly received by a host device and removed from the host
device. Such removable integrated circuit cards typically have a
set of interface pads (or interface pins), which are electrically
conductive. The host device may have a card connector configured to
receive the removable integrated circuit card. The card connector
may have electrical contacts that make an electrical connection
with the interface pads when the removable integrated circuit card
is in the card connector.
A removable memory card is an example of a removable integrated
circuit card. A removable memory card is an electronic data storage
device that may be repeatedly received by a host device and removed
from the host device. A removable memory card may have non-volatile
memory. Examples of removable memory cards include, but are not
limited to, a Secure Digital (SD) Card, a micro SD card, and a
Universal Flash Storage (UFS) card.
Removable integrated circuit cards, such as removable memory cards,
support a set of one or more capabilities. An example capability is
an operating voltage. The operating voltage may be supplied to the
removable integrated circuit card by the host device. For the sake
of example, the removable integrated circuit card might be only
capable of operating at a high voltage level (e.g., 3.3V) or might
be capable of operating at a low voltage level (e.g., 2.5V). The
operating voltage may be used for signals on a signaling interface
between the removable integrated circuit card and the host device,
as well as for other functions in the removable integrated circuit
card. An advantage of the low voltage level is power saving, which
can be important especially for battery operated host devices.
Prior to operating the removable integrated circuit card, the host
device needs to determine the capabilities of the removable
integrated circuit card. In one possible procedure, the host device
and removable integrated circuit card undergo an initialization
procedure in which information is exchanged between the host device
and removable integrated circuit card. In one possible procedure,
the host device reads a register in the removable integrated
circuit card to learn the capabilities.
A drawback with some conventional approaches for learning the
capabilities of a removable integrated circuit card is that the
removable integrated circuit card may need to support a legacy
capability in order for the host device to learn the capabilities.
For example, during initialization the host device may determine
whether the removable integrated circuit card supports a high
voltage level (e.g., 3.3V) or a low voltage level (e.g., 2.5V). In
one approach, the host device provides the high voltage level
(e.g., 3.3V) prior to determining at which voltage level the
removable integrated circuit card is capable of operating. The high
voltage level may be used on the signaling interface during
initialization. If the removable integrated circuit card is capable
of operating at the low voltage level, then host device switches
over to the low voltage level. However, this approach requires a
removable integrated circuit card that is capable of operating at
the low voltage level to also support the high voltage level.
Another drawback with some conventional approaches for learning the
capabilities of a removable integrated circuit card is that host
drivers may need to be updated when a new capability is introduced
in a removable integrated circuit card. For example, techniques
that rely upon the host device reading a register may require that
the host drivers be updated if the removable integrated circuit
card supports a new capability.
DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts one embodiment of a system having a host device that
is configured to accept a removable integrated circuit card.
FIG. 2 depicts a flowchart of one embodiment of a process of a host
device interacting with a removable integrated circuit card.
FIGS. 3a, 3b, 3c, and 3d depict embodiments of removable integrated
circuit cards with different physical configurations of capability
pads.
FIG. 4 depicts an embodiment of a removable integrated circuit card
having two capability pads.
FIGS. 5a, 5b, 5c, and 5d depict an embodiment with different
voltages on capability pads of a removable integrated circuit card
to indicate different sets of capabilities.
FIG. 6 depicts one embodiment of components of a host device that
are configured to sense a physical configuration of one or more
capability pads of an integrated circuit card.
FIG. 6a and FIG. 6b provide details how one embodiment of the
system of FIG. 6 may be applied for two different removable
integrated circuit cards.
FIG. 7 depicts one embodiment of components of a host device that
are configured to distinguish between four different physical
configurations of one or more capability pads.
FIGS. 7a, 7b, 7c, and 7d provide details of how one embodiment of
the system of FIG. 7 may be applied for four different physical
configurations of capability pads.
FIG. 8 depicts one embodiment of a system in which a capability pad
is used to provide power to the removable integrated circuit card
during operation.
FIG. 9 depicts one embodiment of a card connector.
FIG. 10 depicts a flowchart of one embodiment a process of
operating a removable memory card.
FIG. 11 depicts a flowchart of one embodiment a process of
determining a capability set of a removable memory card.
FIG. 12 depicts a flowchart of one embodiment a process of
operating a removable memory card based on a capability set of the
removable memory card.
FIG. 13 depicts one embodiment in which the host device provides
two voltages to the removable integrated circuit card.
FIG. 14 depicts a flowchart of one embodiment of a process of
determining a capability set based on voltages provided by a host
device.
DETAILED DESCRIPTION
The present technology relates to detecting one or more
capabilities of a removable integrated circuit card, such as a
removable memory card. The removable integrated circuit card has a
set of one or more capabilities. Throughout this disclosure, "set
of capabilities" or "capability set" will be understood to mean
that the set includes one or more capabilities. Thus, for brevity
"set of capabilities" or "capability set" may be used instead of
"set of one or more capabilities." An example of a capability is a
power supply voltage at which the removable integrated circuit card
is capable of operating.
In one embodiment, the removable integrated circuit card has one or
more capability pads. A capability pad is an interface pad that may
indicate a capability set of the removable integrated circuit card.
In one embodiment, the capability set is determined by a host
device based on a physical condition of one or more capability
pads. The physical condition may be a physical configuration of one
or more capability pads. In one embodiment, the physical
configuration includes a size of a capability pad. In one
embodiment, the physical configuration includes a location of a
capability pad. In one embodiment, the physical configuration
includes the absence of a capability pad. Thus, factors including,
but not limited to, size, location, and/or presence/absence of a
capability pad may indicate a capability set.
In one embodiment, the host device is able to sense the physical
condition of the one or more capability pads when the removable
integrated circuit card is in a card connector of the host device.
The host device may determine the capability set of the removable
integrated circuit card based on the physical configuration. In
some embodiments, the removable integrated circuit card is not
required to support both a legacy capability and a newer capability
in order for the host device to learn the capability set. In some
embodiments, the capability set is learned with the removable
integrated circuit card powered off. In some embodiments, the host
device has hardware that is used to detect a capability set and
make proper connections to the removable integrated circuit card
based on the capability set. Hence, host drivers do not need to be
updated when a new capability is added to a removable integrated
circuit card.
It is understood that the present invention may be embodied in many
different forms and should not be construed as being limited to the
embodiments set forth herein. Rather, these embodiments are
provided so that this disclosure will be thorough and complete and
will fully convey the invention to those skilled in the art.
Indeed, the invention is intended to cover alternatives,
modifications and equivalents of these embodiments, which are
included within the scope and spirit of the invention as defined by
the appended claims. Furthermore, in the following detailed
description of the present invention, numerous specific details are
set forth in order to provide a thorough understanding of the
present invention. However, it will be clear to those of ordinary
skill in the art that the present invention may be practiced
without such specific details.
The terms "top"/"bottom," "upper"/"lower" and
"vertical"/"horizontal," and forms thereof, as may be used herein
are by way of example and illustrative purposes only, and are not
meant to limit the description of the technology inasmuch as the
referenced item can be exchanged in position and orientation. Also,
as used herein, the terms "substantially" and/or "about" mean that
the specified dimension or parameter may be varied within an
acceptable manufacturing tolerance for a given application. In one
embodiment, the acceptable manufacturing tolerance is .+-.0.25% of
a defined component dimension.
FIG. 1 depicts one embodiment of a system having a host device 102
that is configured to accept a removable integrated circuit card
104. The host device 102 could be, but is not limited to, a desktop
computer, laptop computer, a notepad computer, a digital camera, a
cellular telephone, a personal digital assistant, a portable media
player, an electronic keyboard, or a video game console.
In one embodiment, the removable integrated circuit card 104 is a
removable memory card. However, the removable integrated circuit
card 104 is not limited to being a memory card. A removable memory
card is an electronic data storage device. Examples of removable
memory cards include, but are not limited to, a Secure Digital (SD)
Card, a micro SD card, and a Universal Flash Storage (UFS) card.
The removable memory card may be configured to operate in
accordance with any number of standards. In one embodiment, the
removable integrated circuit card 104 is configured to operate
according to the PCI-Express.TM. (PCIe) expansion bus standard
adapted into a .mu.SD card form factor. However, it is understood
that the removable integrated circuit card 104 may be configured
according to any of a variety of other standard and non-standard
bus protocols. As one further example, the removable integrated
circuit card 104 may be configured to operate according to the
UHS-II standard. In another example, the removable integrated
circuit card 104 may be configured as a Universal Flash Storage
(UFS) card and may be configured to operate according to the UFS
specification.
The removable integrated circuit card 104 has a number of interface
pads 106. The interface pads 106 may also be referred to as
interface pins. The interface pads 106 provide an electrical
interface with the host device 102. Each interface pad 106 is made
from an electrical conductor, such as metal. The integrated circuit
card 104 in FIG. 1 has a single row of interface pads 106, but
other configurations are possible. For example, some removable
integrated circuit cards have two rows of interface pads. The host
device 102 provides power to the removable integrated circuit card
104 via one or more of the interface pads 106. The host device 102
and the removable integrated circuit card 104 may communicate over
one or more the interface pads 106 using signals whose voltage is
based on the voltage level of the power provided by the host device
102. In one embodiment, the host device 102 provides a clock signal
over one of the interface pads 106. The interface pads 106 may
allow for other functionality.
In one embodiment, one or more of the interface pads 106 serves to
indicate the capability set of the removable integrated circuit
card 104. For the sake of discussion, interface pad 106a is a
capability pad. Note that a capability pad 106a is formed from an
electrical conductor, such as a metal. In some embodiments, the
removable integrated circuit card 104 has more than one capability
pad 106a. In some embodiments, the absence of a capability pad
indicates a capability set of the removable integrated circuit card
104.
The host device 102 has a card connector 108 that is configured to
accept the removable integrated circuit card 104. In one
embodiment, the card connector 108 includes a slot in the host
device 102 and a tray that fits into the slot. The tray is
configured to accept the integrated circuit card 104. Therefore,
the removable integrated circuit card 104 may be repeatedly
received by the host device 102 and removed from the host device
102. The card connector 108 has a number of electrical contacts
110. When the integrated circuit card 104 is loaded into the card
connector 108, the interface pads 106 are in electrical contact
with the electrical contacts 110.
In one embodiment, the host device 102 is configured to determine
the capability set of the removable integrated circuit card 104. In
one embodiment, the host device 102 is configured to determine the
capability set of the removable integrated circuit card 104 based
on a physical condition of the one or more capability pads 106a.
The physical condition could be, but is not limited to, a physical
configuration of the one or more capability pads 106a or an
electrical signal (e.g., voltage) that appears at respective ones
of the one or more capability pads 106a. The physical configuration
of the one or more capability pads 106a may include, but is not
limited to, a length of a capability pad, a width of a capability
pad, the number of capability pads, a physical location of a
capability pad, and the presence or absence of a capability pad or
portion thereof at a target location on the removable integrated
circuit card 104.
In one embodiment, the sensing circuit 112 in the host device 102
is configured to determine the physical condition of the one or
more capability pads. In one embodiment, one or more of the
electrical contacts 110 serves as a sensing contact. In FIG. 1, for
the purpose of illustration, there are two sensing contacts 110a,
110b. There may be more or fewer than two sensing contacts. The
term sensing contact may be applied to any electrical contact 110
that is used by the sensing circuit 112 whether or not the sensing
circuit 112 senses a signal (e.g., voltage) at the sensing contact.
Each sensing contact coincides with a target location 114 on the
removable integrated circuit card 104, when the removable
integrated circuit card 104 is in the card connector 108. For
example, sensing contact 110a will be in contact with target
location 114a and sensing contact 110b with be in contact with
target location 114b when the removable integrated circuit card 104
is in the card connector 108. Note that reference numeral 114 may
be used to refer to a target location in general without reference
to a specific target location.
In one embodiment, each sensing contact 110a, 110b is configured to
sense at a target location on the removable integrated circuit card
104. For example, sensing contact 110a may be configured to sense
at target location 114a when the integrated circuit card 104 is in
the card connector 108. Likewise, sensing contact 110b may be
configured to sense at target location 114b when the integrated
circuit card 104 is in the card connector 108. The target location
114 might or might not coincide with the location of a capability
pad. As will be discussed in more detail below, the capability pad
106a could be shorter than depicted in FIG. 1. In this case, target
location 114b might not coincide with the capability pad 106a. In
this case, it may be that sensing contact 110a will be in
electrical contact with the capability pad at target location 114a
when the integrated circuit card 104 is in the card connector 108.
However, in this example, sensing contact 110b might not be in
electrical contact with any capability pad (or even with any
interface pad 106) when the integrated circuit card 104 is in the
card connector 108.
The host device 102 has a host processor 116 and host memory 118.
In one embodiment, the host memory 118 stores code (software) such
as a set of instructions (including firmware), and the host
processor 116 is operable to execute the set of instructions to
sense a physical condition of the one or more capability pads,
determine a capability set of the removable integrated circuit card
based on the physical condition, and/or operate the removable
integrated circuit card based on the capability set. In some
embodiments, the combination of sensing circuit 112 and host
processor 116 are referred to as one or more control circuits. In
one embodiment, the combination of host processor 116, host memory
118, and sensing circuit 112 is referred to as one or more control
circuits. The one or more control circuits are not required to
include processor 116. In some embodiments, the host device 102 has
hardware that senses a physical condition of the one or more
capability pads, determines a capability set of the removable
integrated circuit card based on the physical condition, and/or
operates the removable integrated circuit card based on the
capability set. A control circuit can include a processor, PGA
(Programmable Gate Array, FPGA (Field Programmable Gate Array),
ASIC (Application Specific Integrated Circuit), integrated circuit
or other type of circuit.
The removable integrated circuit card 104 has one or more control
circuits 120 configured to operate the memory card in accordance
with the capability set. The one or more control circuits 120 could
include a processor, PGA (Programmable Gate Array, FPGA (Field
Programmable Gate Array), ASIC (Application Specific Integrated
Circuit), integrated circuit or other type of circuit. In one
embodiment, the removable integrated circuit card 104 is a
removable memory card having non-volatile memory, and the one or
more control circuits 120 includes a memory controller.
FIG. 2 depicts a flowchart of one embodiment of a process 200 of a
host device interacting with a removable integrated circuit card.
The removable integrated circuit card 104 may be a memory card, but
is not limited thereto. Reference will be made to FIG. 1 to discuss
process 200; however, process 200 is not limited to FIG. 1.
Step 202 includes the host device 102 receiving a removable
integrated circuit card 104 in a card connector 108 of the host
device 102. The removable integrated circuit card 104 may have one
or more capability pads 106a.
Step 204 includes the host device 102 detecting a physical
condition of the one or more capability pads 106a of the removable
integrated circuit card 104. In one embodiment, the host device 102
detects a physical configuration of the one or more capability pads
106a. In one embodiment, the host device 102 detects a shape of a
capability pad 106a. In one embodiment, the host device 102 detects
a length of a capability pad 106a. In one embodiment, the host
device 102 detects a width of a capability pad 106a. In one
embodiment, the host device 102 detects the number of capability
pads 106a in a target region of the removable integrated circuit
card 104. In one embodiment, the host device 102 detects a voltage
at a capability pad 106a.
Step 206 includes the host device 102 determining a capability set
of the removable integrated circuit card 104 based on the physical
condition. In one embodiment, the host device 102 determines a
voltage level at which the removable integrated circuit card 104 is
capable of operating. For example, the host device 102 may
determine whether the removable integrated circuit card 104
supports a 3.3V level or a 2.5V level.
Step 208 includes the host device 102 interacting with the
removable integrated circuit card 104 based on the capability set
of the integrated circuit card 104. In one embodiment, the host
device 102 provides a power supply voltage to the removable
integrated circuit card 104, wherein the magnitude of the power
supply voltage depends on a capability set of the removable
integrated circuit card 104. For example, a circuit in the host
device 102 may operate a switch to, for example, connect the power
supply voltage. In one embodiment, the host device 102 communicates
with the removable integrated circuit card 104 using signals whose
voltage level is specified by the capability set of the removable
integrated circuit card 104. In one embodiment, this communication
is over one or more interface pads other than the one or more
capability pads 106a. In one embodiment, this communication is over
one or more capability pads 106a.
In some embodiments, steps 204 and 206 are performed while the
removable integrated circuit card 104 is powered off. Steps 204 and
206 may be performed prior to the host device 102 exchanging
information with the removable integrated circuit card 104 as part
of an initialization process of the removable integrated circuit
card 104. Steps 204 and 206 may be performed prior to the host
device 102 sending any commands to the removable integrated circuit
card 104. Steps 204 and 206 may be performed without the host
device 102 reading any registers within the removable integrated
circuit card 104.
As discussed above, some techniques may require that a removable
integrated circuit card 104 that supports a newer capability (such
as low voltage level) also support a legacy capability (such as a
legacy higher voltage level). Process 200 does not have such a
requirement. A factor in the ability to of process 200 to avoid
such a requirement is that the host device 102 is able to learn the
capability set very early. For example, the host device 102 can
learn the capability set while the removable integrated circuit
card 104 is powered off, prior to the host device 102 exchanging
information with the removable integrated circuit card 104, prior
to the host device 102 sending any commands to the removable
integrated circuit card 104, and/or without the host device 102
reading any registers within the removable integrated circuit card
104. Hence, the design of the removable integrated circuit card 104
may be simplified, thereby providing considering cost savings.
In one embodiment, a physical configuration of one or more
capability pads indicates a capability set of a removable
integrated circuit card 104. FIGS. 3a, 3b, 3c, and 3d depict four
different physical configurations for an embodiment of a capability
pad of an integrated circuit card 104. The four different physical
configurations may therefore be used to indicate up to four
different capability sets. Alternatively, any two different
physical configurations may be used to indicate up to two different
capability sets. Alternatively, any three different physical
configurations may be used to indicate up to three different
capability sets.
FIG. 3a depicts an embodiment of a removable integrated circuit
card 104 having capability pad 106a-1. FIG. 3b depicts an
embodiment of a removable integrated circuit card 104 having
capability pad 106a-2. FIG. 3c depicts an embodiment of a removable
integrated circuit card 104 having capability pad 106a-3. FIG. 3d
depicts an embodiment of a removable integrated circuit card 104
that does not have a capability pad. Target locations 114a and 114b
are also depicted in each of FIGS. 3a, 3b, 3c, and 3d. The target
locations 114a and 114b are locations in the respective removable
integrated circuit cards 104 that coincide with sense contacts when
the removable integrated circuit card 104 is in the card connector
108.
In one embodiment, the physical configuration of the one or more
capability pads includes a length of one or more capability pads
106a. Thus, in one embodiment, the length of a capability pad 106a
may be used to indicate a capability set of the removable
integrated circuit card 104. For example, the capability pad 106a-1
in FIG. 3a is longer than the capability pad 106a-2 in FIG. 3b.
Likewise, the capability pad 106a-1 in FIG. 3a is longer than the
capability pad 106a-3 in FIG. 3c. In one embodiment, the host
device 102 senses at target locations 114a and 114b in order to
determine the length of the capability pad 106a.
In one embodiment, the location of the capability pad 106a may be
used to indicate a capability set of the removable integrated
circuit card 104. For example, the capability pad 106a-2 in FIG. 3b
is located closer to a front edge 302 of the removable integrated
circuit card 104 than the capability pad 106a-3 in FIG. 3c. In one
embodiment, the host device 102 senses at target locations 114a and
114b in order to determine the location of the capability pad
106a.
In one embodiment, the presence or absence of a capability pad 106a
may be used to indicate a capability set of the removable
integrated circuit card 104. For example, in FIG. 3d, the removable
integrated circuit card 104 does not have a capability pad 106a. In
one embodiment, the host device 102 senses at target locations 114a
and 114b in order to determine whether or not the removable
integrated circuit card 104 has a capability pad 106a at either of
those target locations.
In one embodiment, the number of capability pads is used to
indicate a capability set of a removable integrated circuit card
104. The number of number of capability pads is an example of a
physical configuration of one or more capability pads. FIG. 4
depicts an embodiment of a removable integrated circuit card 104
having two capability pads 106a-4 and 106a-5. In one embodiment,
the host device 102 senses at target locations 114a and 114b in
order to determine how many capability pads that the removable
integrated circuit card 104 has. In one embodiment, the host device
102 distinguishes between a single capability pad 106a-1 in FIG. 3a
and two capability pads 106a-4 and 106a-5 in FIG. 4. In one
embodiment, the host device 102 distinguishes between a single
capability pad 106a-2 in FIG. 3b and two capability pads 106a-4 and
106a-5 in FIG. 4. In one embodiment, the host device 102
distinguishes between a single capability pad 106a-3 in FIG. 3c and
two capability pads 106a-4 and 106a-5 in FIG. 4.
In one embodiment, the two capability pads 106a-4, 106a-4 are
electrically connected internally in removable integrated circuit
card 104. This allows the two relatively short capability pads
106a-4, 106a-4 to be interpreted by the host device 102 as a single
relative long capability pad (see, for example, capability pad
106a-1 in FIG. 3a). Thus, such an internally connected
configuration of the two capability pads 106a-4, 106a-4 in FIG. 4
is an alternative to capability pad 106a-1 in FIG. 3a.
In one embodiment, the physical condition of one or more capability
pads 106a that the host device 102 detects are voltages at
respective capability pads 106a. In some embodiments, the removable
integrated circuit card 104 provides voltages on respective
capability pads 106a in order to indicate its capability set. FIGS.
5a-5d depict how voltages on a pair of capability pads may be used
to indicate which capability set of up to four capability sets is
supported by the integrated circuit card 104.
In one embodiment, the removable integrated circuit card 104
creates the voltages on the capability pads 106a based on voltages
that it receives on other interface pads 106. For example, the
integrated circuit card 104 may receive a first voltage (G) on
interface pad 106c and a second voltage (V) on interface pad 106d.
The host device 102 may provide these two voltages. The two
voltages could be any two voltages that have a different magnitude.
These may be voltages that the host device 102 would normally
provide during operation. However, the host device 102 is not
required to learn whether the removable integrated circuit card 104
is capable of operating at, for example, 3.3V or 2.5V in order to
provide the voltages. The term G is used to indicate that the first
voltage may be a ground voltage. The term V is used to indicate
that the second voltage may be a positive voltage. Other terms
could be used such as providing Vs on interface pad 106c and
providing VD on interface pad 106d, where VD has a larger magnitude
than Vs. In this context, Vs could be considered to be ground. Note
that it is not required that one of the voltages be ground.
Based on the two voltages, there are four combinations of voltages
on the capability pads 106a depicted in FIG. 5a-5d. Specifically,
in FIG. 5a, the removable integrated circuit card 104 connects the
first voltage (G) to capability pad 106a-6 and also to capability
pad 106a-7. In FIG. 5b, the removable integrated circuit card 104
connects the second voltage (V) to capability pad 106a-6 and
connects the first voltage (G) to capability pad 106a-7. In FIG.
5c, the removable integrated circuit card 104 connects the first
voltage (G) to capability pad 106a-6 and connects the second
voltage (V) to capability pad 106a-7. In FIG. 5d, the removable
integrated circuit card 104 connects the second voltage (V) to
capability pad 106a-6 and also connects the second voltage (V) to
capability pad 106a-7.
A concept in FIGS. 5a to 5d may be modified to cases in which there
are more or fewer than two capability pads 106a. For example, with
one capability pad 106a the removable integrated circuit card 104
may connect either the first voltage (G) or the second voltage (V)
to the single capability pad 106a. In this manner, the removable
integrated circuit card 104 may indicate a capability set out of
two possible capability sets. As another example, with three
capability pads 106a the removable integrated circuit card 104 may
connect either the first voltage (G) or the second voltage (V) to
respective ones of the three capability pads 106a. In this manner,
the removable integrated circuit card 104 may indicate a capability
set out of eight possible capability sets.
As noted above, the host device 102 is able to determine a
capability set of the integrated circuit card 104 based on a
physical condition of the one or more capability pads 106a. In some
embodiments, the physical condition of the one or more capability
pads includes a physical configuration of the one or more
capability pads 106a. The physical configuration could include one
or more of, but is not limited to, a length of a capability pad, a
width of a capability pad, the number of capability pads, a
physical location of a capability pad, and the presence or absence
of a capability pad or portion thereof at a target location on the
removable integrated circuit card 104.
FIG. 6 depicts one embodiment of components of a host device 102
that are configured to sense a physical configuration of one or
more capability pads of an integrated circuit card 104. The
components are further able to determine a capability set of the
integrated circuit card 104 based on the sensed physical condition.
The components are further able to operate the removable integrated
circuit card 104 based on the capability set. In one embodiment,
the components are able to determine a physical length of a
capability pad 106a. In one embodiment, the components are able to
distinguish between a longer capability pad (e.g., capability pad
106a-1 in FIG. 3a) and a shorter capability pad (e.g., capability
pad 106a-2 in FIG. 3b).
A removable integrated circuit card 104 is depicted in dashed lines
to indicate a relative location of the removable integrated circuit
card 104 to certain components of the host device 102, such as
sensing contacts 110a, 110b. An example in which there are two
target locations 114a, 114b on the removable integrated circuit
card 104 is depicted. There may be more or fewer than two target
locations 114 on the removable integrated circuit card 104.
The host device 102 provides voltage (+V) to Node 602, which is
connected to one end of resistive element 604. In one embodiment,
resistive element 604 includes a resistor. The resistive element
604 could include other circuit elements such as a transistor. For
example, a transistor may be configured to operate as a resistive
element. The other end of resistive element 604 is connected to
Node 606, which is connected to sensing contact 110a. The host
device 102 connects sensing contact 110b to ground. In one
embodiment, the removable integrated circuit card 104 is not
powered on when the host device 102 senses the physical condition
of the one or more capability pads. However, note that if the
capability pad is electrically connected to both sensing contact
110a, 110b, then there will be a short circuit between the two
sensing contacts 110a, 110b. This short circuit will connect Node
606 to ground, with the voltage (+V) that is applied to resistive
element 604 being dissipated across resistive element 604. On the
other hand, if the capability pad is not electrically connected to
both sensing contact 110a, 110b, then the voltage at Node 606 will
be the voltage at Node 602 minus the voltage across resistive
element 604. Assuming that resistive element 604 is a resistor and
no current flows through the resistor, the voltage at Node 606 will
be +V. Resistive element 604 is not required to be a resistor.
Resistive element 604 could be any resistive element that can
absorb the voltage difference between Node 602 and Node 606 when
Node 606 is grounded.
The voltage detector 608 is configured to detect a voltage at Node
606. In other words, the voltage detector 608 is configured to
detect a voltage at sensing contact 110a. In one embodiment, the
voltage detector 608 compares the magnitude of the voltage at Node
606 with a reference voltage. The voltage detector 608 outputs a
signal to the capability determination 610 that indicates whether
the voltage at Node 606 is greater than or less than the reference
voltage. In one embodiment, voltage detector 608 comprises a
comparator. The comparator inputs a reference voltage and the
voltage at Node 606, and outputs a signal that indicates whether
the voltage at Node 606 is greater than the reference voltage. In
one embodiment, the voltage detector 608 and resistive element 604
are part of the sensing circuit 112.
The capability determination 610 is configured to determine the
capability set based on the signal from the voltage detector 608.
In one embodiment, if the signal indicates that the voltage at Node
606 is greater than the reference voltage, then this indicates that
the removable integrated circuit card 104 has a relatively short
capability pad 106a (such as in FIG. 3b). In one embodiment, if the
signal indicates that the voltage at Node 606 is less than the
reference voltage, then this indicates that the removable
integrated circuit card 104 has a relatively long capability pad
106a (such as in FIG. 3a).
The capability determination 610 then determines which of two sets
of capabilities that the removable integrated circuit card 104 has
based on whether the removable integrated circuit card 104 has a
relatively long capability pad 106a or a relatively short
capability pad 106a. In one embodiment, one of the capabilities in
the first set is that the removable integrated circuit card 104 is
configured to operate at a higher voltage level (e.g., 3.3V). In
one embodiment, one of the capabilities in the second set is that
the removable integrated circuit card 104 is configured to operate
at a lower voltage level (e.g., 2.5V). Note that 3.3V and 2.5V are
used as examples, and the other voltages could be used.
Card operation 612 is configured to operate the removable
integrated circuit card 104 based on the capability set determined
by capability determination 610. In one embodiment, card operation
612 selects either a 3.3V power supply 614 or a 2.5V power supply
616 based on the capability set. Card operation 612 controls switch
618 to connect either 3.3V power supply 614 or 2.5V power supply
616 to electrical contact 110c. Electrical contact 110d is
connected to ground.
The capability determination 610 and the card operation 612 could
be implemented in software, hardware, or a combination of hardware
and software. In one embodiment, the capability determination 610
and the card operation 612 are implemented by executing
instructions on host processor 116. The instructions may be stored
in host memory 118. In one embodiment, the host components in FIG.
6 (e.g., resistive element 604, voltage detector 608, capability
determination 610, card operation 612, switch 616, 3.3V power
supply 614, and/or 2.5V power supply) are referred to as a control
circuit. Any subset of host components in FIG. 6 could be referred
to as a control circuit.
FIG. 6a and FIG. 6b provide details how the system of FIG. 6 may be
applied for two different removable integrated circuit cards 104.
FIG. 6a depicts a removable integrated circuit card 104 having a
capability pad 106a-1 that is consistent with the removable
integrated circuit cards 104 depicted in FIG. 3a. FIG. 6b depicts a
removable integrated circuit card 104 having a capability pad
106a-2 that is consistent with the removable integrated circuit
cards 104 depicted in FIG. 3b.
FIG. 6a depicts an example with a relatively long capability pad
106a-1. The capability pad 106a-1 is connected to ground by way of
sensing contact 110b. Therefore, Node 606 will be at ground. This
corresponds to a logical "0", which may be interpreted as detection
of a long capability pad 106a-1. It also may be interpreted as in
indication that the removable integrated circuit cards 104 supports
"Set 0" of capabilities. The switch 618 may be set in accordance
with the detection of a long capability pad 106a-1.
FIG. 6b depicts an example with a relatively short capability pad
106a-2. The capability pad 106a-2 is not connected to ground.
Therefore, assuming that there is no voltage drop across resistive
element 604 (e.g., resistive element 604 is a resistor with no
current flowing through the resistor), Node 606 will be at +V. This
condition also may be interpreted as in indication that the
removable integrated circuit cards 104 supports "Set 1" of
capabilities. The switch 618 may be set in accordance with the
detection of a short capability pad 106a-2.
As noted above, an embodiment of the host device 102 in FIG. 6 is
able to determine which capability set out of two capability sets
are supported by a removable integrated circuit card 104. In some
embodiments, the host device 102 is able to determine which
capability set out of four possible capability sets is supported by
a removable integrated circuit card 104. To do so, the host device
102 is able to distinguish between four different physical
configurations of the one or more capability pads 106a. For
example, the host device 102 may be able to distinguish between the
four different physical configurations depicted in FIGS. 3a to
3d.
FIG. 7 depicts one embodiment of components of a host device 102
that are configured to distinguish between the four different
physical configurations of one or more capability pads 106a. The
components are further able to determine a capability set from four
sets of capabilities based on the four different physical
configurations. The components are further able to operate the
integrated circuit card 104 based on the determined capability set.
In one embodiment, the components are able to distinguish between
the four different physical configurations depicted in FIGS. 3a to
3d.
A removable integrated circuit card 104 is depicted in dashed lines
in FIG. 7 to indicate a relative location of the removable
integrated circuit card 104 to certain components of the host
device 102, such as sensing contacts 110a, 110b. An example in
which there are two target locations 114a, 114b on the removable
integrated circuit card 104 is depicted. There may be more or fewer
than two target locations 114 on the removable integrated circuit
card 104. The one or more capability pads 106a are not expressly
depicted in FIG. 7. FIGS. 7a to 7d depict four different physical
configurations for the one or more capability pads 106a. In one
embodiment, the one or more capability pads 106a are internally
connected to ground when the host device 102 senses the capability
pads 106a.
The host device 102 provides voltage (+V) to Node 702a, which is
connected to one end of first resistive element 704a. In one
embodiment, first resistive element 704a includes a resistor. The
other end of first resistive element 704a is connected to Node
706a, which is connected to sensing contact 110a.
The host device 102 provides voltage (+V) to Node 702b, which is
connected to one end of second resistive element 704b. In one
embodiment, second resistive element 704b includes a resistor. The
other end of second resistive element 704b is connected to Node
706b, which is connected to sensing contact 110b.
First resistive element 704a could be any resistive element that
can absorb the voltage difference between Node 702a and Node 706a
when Node 706a is grounded. For example, if Node 706a is at ground
the voltage across the first resistive element 704a will be +V.
Likewise, second resistive element 704b could be any resistive
element that can absorb the voltage difference between Node 702a
and Node 706b when Node 706b is grounded.
In one embodiment, the removable integrated circuit card 104 is not
powered on when the host device 102 senses the physical
configuration of the one or more capability pads. However, the one
or more capability pads 106a are internally connected to ground
when the host device 102 senses the capability pad 106a. In one
embodiment, the removable integrated circuit card 104 connects the
capability pad 106a to a ground that is supplied on capability pad
106a (see, for example, electrical contact 110d).
Voltage detector 708a is configured to sense a voltage at Node
706a. Likewise, voltage detector 708b is configured to sense a
voltage at Node 706b. In one embodiment, voltage detector 708a,
voltage detector 708b, first resistive element 704a, and second
resistive element 704b are part of the sensing circuit 112.
Capability determination 710 determines the capability set based on
a first signal from voltage detector 708a and a second signal from
voltage detector 708b. Card operation 712 operates the removable
integrated circuit card 104 in accordance with the capability set.
Card operation 712 controls switch 714 to select either the 3.3V
power supply 716 or the 2.5V power supply 718.
The capability determination 710 and the card operation 712 could
be implemented in software, hardware, or a combination of hardware
and software. In one embodiment, the capability determination 710
and the card operation 712 are implemented by executing
instructions on host processor 116. The instructions may be stored
in host memory 118. In one embodiment, the host components in FIG.
7 (e.g., resistive elements 704a, 704b, voltage detectors 708a,
708b, capability determination 710, card operation 712, switch 714,
3.3V power supply 716, and/or 2.5V power supply 718) are referred
to as a control circuit. Any subset of host components in FIG. 7
could be referred to as a control circuit.
FIG. 7a will now be discussed in order to illustrate sensing of
capability pad 106a-1. As noted in the discussion of FIG. 7, host
device 102 provides voltage (+V) to Node 702a, which is connected
to one end of first resistive element 704a. The other end of first
resistive element 704a is connected to Node 706a, which is
connected to sensing contact 110a. Also, host device 102 provides
voltage (+V) to Node 702b, which is connected to one end of second
resistive element 704b. The other end of second resistive element
704b is connected to Node 706b, which is connected to sensing
contact 110b. The external surface of capability pad 106a-1 is
electrically connected to both sensing contacts 110a, 110b.
The capability pad 106a-1 is internally grounded. By this it is
meant that the pathway to ground is provided within integrated
circuit card 104. In other words, the host device 102 does not
apply ground directly to the external surface of the capability pad
106a-1. However, the host device may supply ground to electrical
contact 110d. There may be an electrical connection within the
integrated circuit card 104 between the capability pad 106a-1 and
electrical contact 110d in order to ground the capability pad
106a-1.
Given that capability pad 106a-1 is internally grounded, Node 706a
will be at ground. Also, given that capability pad 106a-1 is
internally grounded, Node 706b will also be at ground. For purpose
of discussion, a ground will be interpreted as a logic low or as
"0." Thus, voltage detector 708a outputs a "0". Likewise, voltage
detector 708b outputs a "0".
Returning again to the discussion of FIG. 7, the voltage detectors
708a, 708b provide their respective outputs to the capability
determination 710. In this example, the "00" is interpreted by the
capability determination 710 as a "long pad". Moreover, the "00"
indicates which of the four different sets of capabilities the
integrated circuit card 104 has. Capability determination 710
informs card operation 712 which capability set the integrated
circuit card 104 has. Card operation 712 controls switch 714 based
on the "00" detection. In other words, card operation 712 controls
switch 714 based on the determined capability set.
FIG. 7b will now be discussed in order to illustrate sensing of
capability pad 106a-2. As noted in the discussion of FIG. 7, host
device 102 provides voltage (+V) to Node 702a, which is connected
to one end of first resistive element 704a. The other end of first
resistive element 704a is connected to Node 706a, which is
connected to sensing contact 110a. Also, host device 102 provides
voltage (+V) to Node 702b, which is connected to one end of second
resistive element 704b. The other end of second resistive element
704b is connected to Node 706b, which is connected to sensing
contact 110b. In this example, the external surface of capability
pad 106a-2 is electrically connected to sensing contact 110a.
However, the external surface of capability pad 106a-2 is not
electrically connected to sensing contact 110b, due to the
relatively short length of capability pad 106a-2.
As with the example of FIG. 7A, the capability pad 106a-2 in FIG.
7B is internally grounded. By this it is meant that the pathway to
ground is provided within integrated circuit card 104. In other
words, the host device 102 does not apply ground directly to the
external surface of the capability pad 106a-2. However, the host
device may supply ground to electrical contact 110d. There may be
an electrical connection within the integrated circuit card 104
between the capability pad 106a-2 and electrical contact 110d in
order to ground the capability pad 106a-2.
Given that capability pad 106a-2 is internally grounded, Node 706a
will be at ground. However, Node 706b will not be at ground.
Instead the voltage at Node 706b will be +V minus the voltage drop
across resistive element 704b. Assuming that there is no voltage
drop across second resistive element 704b, the voltage at Node 706b
will be +V. Thus, voltage detector 708a outputs a "0". On the other
hand, voltage detector 708b outputs a "1".
Returning again to the discussion of FIG. 7, the voltage detectors
708a, 708b provide their respective outputs to the capability
determination 710. In this example, the "10" is interpreted by the
capability determination 710 as a "short pad near the front edge
302". Moreover, the "10" indicates which of the four different sets
of capabilities the integrated circuit card 104 has. Capability
determination 710 informs card operation 712 which capability set
the integrated circuit card 104 has. Card operation 712 controls
switch 714 based on the "10" detection. In other words, card
operation 712 controls switch 714 based on the determined
capability set.
FIG. 7c will now be discussed in order to illustrate sensing of
capability pad 106a-3. As noted in the discussion of FIG. 7, host
device 102 provides voltage (+V) to Node 702a, which is connected
to one end of first resistive element 704a. The other end of first
resistive element 704a is connected to Node 706a, which is
connected to sensing contact 110a. Also, host device 102 provides
voltage (+V) to Node 702b, which is connected to one end of second
resistive element 704b. The other end of second resistive element
704b is connected to Node 706b, which is connected to sensing
contact 110b. In this example, the external surface of capability
pad 106a-3 is electrically connected to sensing contact 110b.
However, the external surface of capability pad 106a-3 is not
electrically connected to sensing contact 110a, due to the
relatively short length of capability pad 106a-3 as well as the
physical location of capability pad 106a-3.
As with the examples of FIGS. 7A and 7B, the capability pad 106a-3
in FIG. 7C is internally grounded. By this it is meant that the
pathway to ground is provided within integrated circuit card 104.
In other words, the host device 102 does not apply ground directly
to the external surface of the capability pad 106a-3. However, the
host device may supply ground to electrical contact 110d. There may
be an electrical connection within the integrated circuit card 104
between the capability pad 106a-3 and electrical contact 110d in
order to ground the capability pad 106a-3.
Given that capability pad 106a-3 is internally grounded, Node 706b
will be at ground. However, Node 706a will not be at ground.
Instead the voltage at Node 706a will be +V minus the voltage drop
across first resistive element 704a. Assuming that there is no
voltage drop across first resistive element 704a, the voltage at
Node 706a will be +V. Thus, voltage detector 708a outputs a"1". On
the other hand, voltage detector 708b outputs a "0".
Returning again to the discussion of FIG. 7, the voltage detectors
708a, 708b provide their respective outputs to the capability
determination 710. In this example, the "01" is interpreted by the
capability determination 710 as a "short pad away from the front
edge 302". Moreover, the "01" indicates which of the four different
sets of capabilities the integrated circuit card 104 has.
Capability determination 710 informs card operation 712 which
capability set the integrated circuit card 104 has. Card operation
712 controls switch 714 based on the "01" detection. In other
words, card operation 712 controls switch 714 based on the
determined capability set.
FIG. 7d will now be discussed in order to illustrate a case in
which the integrated circuit card 104 does not have a capability
pad. As noted in the discussion of FIG. 7, host device 102 provides
voltage (+V) to Node 702a, which is connected to one end of first
resistive element 704a. The other end of first resistive element
704a is connected to Node 706a, which is connected to sensing
contact 110a. Also, host device 102 provides voltage (+V) to Node
702b, which is connected to one end of second resistive element
704b. The other end of second resistive element 704b is connected
to Node 706b, which is connected to sensing contact 110b. In this
example, since there is not capability pad (at least to make
contact with sensing contacts 110a, 110b) neither Node 706a or Node
706b is grounded. The voltage at Node 706a will be +V minus the
voltage drop across first resistive element 704a. Assuming that
there is no voltage drop across first resistive element 704a, the
voltage at Node 706a will be +V. Thus, voltage detector 708a
outputs a "1". Likewise, the voltage at Node 706b will be +V minus
the voltage drop across second resistive element 704b. Assuming
that there is no current flowing in second resistive element 704b,
the voltage at Node 706b will be +V. Thus, voltage detector 708b
outputs a "1".
Returning again to the discussion of FIG. 7, the voltage detectors
708a, 708b provide their respective outputs to the capability
determination 710. In this example, the "11" is interpreted by the
capability determination 710 as a "short pad away from the front
edge 302". Moreover, the "11" indicates which of the four different
sets of capabilities the integrated circuit card 104 has.
Capability determination 710 informs card operation 712 which
capability set the integrated circuit card 104 has. Card operation
712 controls switch 714 based on the "11" detection. In other
words, card operation 712 controls switch 714 based on the
determined capability set.
In some embodiments, a capability pad 106a may serve an additional
function while the removable integrated circuit card 104 is being
operated. For example, the capability pad 106a may be used as an
interface pad to supply a voltage to the removable integrated
circuit card 104 during operation. FIG. 8 depicts one embodiment of
a system in which a capability pad 106a is used to provide power to
the removable integrated circuit card 104 during operation.
The system of FIG. 8 is similar to the system in FIG. 7, but adds a
1.2v power supply 802 and a switch 804. The switch 804 may be used
to connect sensing contact 110a to the voltage detector 708a when
the capability of the removable integrated circuit card 104 is
being determined. If the host device 102 determines that the
removable integrated circuit card 104 is configured to operate
using the 1.2V power supply 802, then switch 804 is connected to
the 1.2V power supply 802. Therefore, the 1.2V power supply 802 is
connected to the sensing contact 110a. Therefore, the 1.2V power
supply 802 is connected to a capability pad 106a (capability pad
not depicted in FIG. 8) during operation of the removable
integrated circuit card 104. On the other hand, if the host device
102 determines that the removable integrated circuit card 104 is
not configured to operate using the 1.2V power supply 802, then the
switch 804 is not connected to the 1.2V power supply 802 during
operation of the removable integrated circuit card 104. Note that
1.2V is used as an example and that other voltages could be used
instead of 1.2V. In one embodiment in which a capability pad 102a
is used to provide a voltage during operation, the existence of the
capability pad indicates that the removable integrated circuit card
104 supports operating at the voltage. The existence of the
capability pad can be determined using various techniques disclosed
herein.
In one embodiment, even if the 1.2V power supply 802 is connected
to a capability pad 106a, either the 3.3V power supply 716 or the
2.5V power supply 718 can be connected to interface pad 106d (see
electrical contact 110c). Thus, the removable integrated circuit
card 104 could be provided with more than one power supply.
In one embodiment, the host components in FIG. 8 (e.g., resistive
elements 704a, 704b, voltage detectors 708a, 708b, capability
determination 710, card operation 712, switch 714, 3.3V power
supply 716, 2.5V power supply 718, and/or 1.2V power supply 802,
and/or switch 804) are referred to as a control circuit. Any subset
of host components in FIG. 8 could be referred to as a control
circuit.
The concept depicted in FIG. 8 can be extended to use the
capability pad 106a for functions other than receiving a power
supply during operation. In one embodiment, instead of connecting
1.2V power supply 802 to the sensing contact 110a (and hence to a
capability pad 106a), sensing contact 110a is connected to a ground
during operation of the removable integrated circuit card 104. In
one embodiment, instead of connecting 1.2V power supply 802 to the
sensing contact 110a (and hence to a capability pad 106a), sensing
contact 110a is connected to a driver in the host device 102 that
provides a signal over a data line during operation. Hence, the
capability pad 106a could have a dual use of indicating a
capability set and transferring data during operation under the
capability set. In one embodiment, instead of connecting 1.2V power
supply 802 to the sensing contact 110a (and hence to a capability
pad 106a), sensing contact 110a is connected to a clock circuit
that provides a clock signal during operation. Hence, the
capability pad 106a could have a dual use of indicating a
capability set and receiving a clock signal during operation.
Recall that FIG. 1 shows that the host device 102 may have a card
connector 108 that is configured to receive the removable
integrated circuit card 104. FIG. 9 depicts further details of one
embodiment of a card connector 108. FIG. 9 shows a cross-sectional
top view of a card connector 108 within a slot 902 in a host device
102 for receiving a tray 904. The tray 904 has an opening 906 that
is configured to hold a removable integrated circuit card 104.
Dashed rectangles in the opening 906 represent possible locations
for the interface pads 106 of the removable integrated circuit card
104. The card connector 108 is configured to receive the tray 904.
The card connector 108 in slot 902 may comprise a number of
electrical contacts 110. The electrical contacts 110 are configured
to mate with the interface pads 106 of the removable integrated
circuit card 104. Two of the electrical contacts 110 serve as
sensing contacts 110a, 110b, which may be used to detect a physical
condition of one or more capability pads 106a. There may be more or
fewer than two sensing contacts.
In some embodiments, the removable integrated circuit card 104 is a
removable memory card. FIG. 10 depicts a flowchart of one
embodiment a process 1000 of operating a removable memory card. The
process 1000 may be performed by one or more control circuits. The
one or more control circuits may be implemented in software,
hardware, or a combination of hardware and software. In one
embodiment, the one or more control circuits include sensing
circuit 112, host processor 116 and host memory 118. Process 1000
could be performed by one or more host components in FIG. 6, FIG.
7, or FIG. 8, but is not limited thereto.
Step 1002 includes providing a voltage to a first end of a
resistive element in a host device 102. In one embodiment, step
1002 is performed by sensing circuit 112. In one embodiment, with
reference to FIG. 6, +V is provided to Node 602, wherein the
voltage is provided to a first end of resistive element 604. In one
embodiment, with reference to FIG. 7, +V is provided to Node 702a,
wherein the voltage is provided to a first end of first resistive
element 704a. Note that in one embodiment, +V is provided to Node
702b, wherein the voltage is provided to a first end of second
resistive element 704b.
A second end of the resistive element is connected to a target
location 114 on a removable memory card 104 in a card connector 108
of the host device 102. Note that this connection could occur as a
result of the removable memory card being inserted into the card
connector 108. Alternatively, the host device 102 could take an
action (such as closing a switch) to connect the second end of the
resistive element is to the target location 114. In one embodiment,
with reference to FIG. 6, the end of resistive element 604 at node
606 is connected to sensing contact 110a. Sensing contact 110a is
connected to target location 114a. In one embodiment, with
reference to FIG. 7, the end of resistive element 704a at node 706a
is connected to sensing contact 110a. Sensing contact 110a is
connected to target location 114a.
Step 1004 includes comparing a magnitude of a voltage at the target
location with a reference voltage. In one embodiment, step 1004 is
performed by sensing circuit 112. With reference to FIG. 6, the
voltage detector 608 may compare the voltage at sensing contact
110a with a reference voltage. Note that in one embodiment, the
host device 102 connects target location 114b to ground in step
1002, such that target location 114b is grounded when voltage
detector 608 senses target location 114a. With reference to FIG. 7,
the voltage detector 708a may compare the voltage at sensing
contact 110a with a reference voltage. Note that in one embodiment,
+V is provided to Node 702b. Thus, +V may be provided to both Node
702a and Node 702b when the voltage detector 608 senses target
location 114a.
Step 1006 includes detecting a physical configuration of one or
more capability pads of the removable memory card based on the
comparison. In one embodiment, step 1006 is performed by host
processor 116. Any of the physical configurations depicted in FIG.
3a, 3b, 3c, 3d, or 4 could be detected, as well as other physical
configurations. Note that step 1006 may be based on additional
information than the comparison of step 1004. In one embodiment,
step 1006 is based on multiple such comparisons. For example, step
1006 can be based on a comparison performed by voltage detector
708a and a comparison performed by voltage detector 708b.
Step 1008 includes determining a capability set of the removable
memory card based on the physical configuration of one or more
capability pads. In one embodiment, step 1008 is performed by host
processor 116. For example, the physical configuration of
capability pad 106a-1 may indicate one capability set and the
physical configuration of capability pad 106a-2 may indicate
another capability set. As another example, the four different
physical configurations depicted in FIGS. 3a to 3d may indicate one
of four different sets of capabilities.
Step 1010 includes operating the removable memory card based on the
capability set while the removable memory card is in the card
connector 108 of the host device 102. In one embodiment, step 1010
is performed by host processor 116. In one embodiment, step 1010
includes providing a voltage to a power supply interface pad of the
removable memory card, wherein a magnitude of the power supply
voltage depends on the determined capability set of the removable
memory card.
FIG. 11 depicts a flowchart of one embodiment a process 1100 of
determining a capability set of a removable integrated circuit card
104, such as a removable memory card. The process 1100 will be
discussed with reference to FIG. 8, but is not limited thereto. In
one embodiment, process 1100 is performed by capability
determination 710. Process 1100 describes some example capabilities
for Set A, Set B, Set C, and Set D. The capability sets are not
limited to these examples. Process 1100 describes further details
of one embodiment of step 1008 of process 1000. Process 1100
describes further details of one embodiment of step 206 of process
200.
Step 1102 includes receiving signals from voltage detectors. In one
embodiment, capability determination 710 receives a first signal
from voltage detector 708a and a second signal from voltage
detector 708b. Step 1102 may also include determining a binary code
from the signals. In an embodiment that is consistent with FIG. 8,
the binary code is two bits. The binary code could have more or
fewer than two bits. In an embodiment that is consistent with FIG.
6, the binary code is one bit. If the host device 102 is configured
to detect voltages at three target locations on the removable
integrated circuit card 104 the binary code could have three
bits.
Step 1104 includes a decision of which branch to take based on the
code. If the binary code is "00", then control passes to step 1106.
Step 1106 includes a determination that the one or more capability
pads has a first physical configuration. In one embodiment, the
first physical configuration is the relatively long capability pad
106a-1 depicted in FIG. 3a.
Step 1108 includes establishing the capability set as Set A. Step
1108 may include storing the binary code in memory. The memory
could be volatile or memory non-volatile memory. In one embodiment,
the binary code is stored in host memory 118. In one embodiment,
Set A includes the capability to operate at a low voltage (e.g.,
2.5V). Set A could also include capabilities such as the capability
to operate with a second voltage (e.g., 1.2V), which would be
provided to a different interface pad than the aforementioned low
voltage.
If the binary code is "10", then control passes to step 1110. Step
1110 includes a determination that the one or more capability pads
has a second physical configuration. In one embodiment, the second
physical configuration is the relatively short capability pad
106a-2 that is close to the front edge 302 of the removable
integrated circuit card 104, as depicted in FIG. 3b.
Step 1112 includes establishing the capability set as Set B. Step
1112 may include storing the binary code in memory. The memory
could be volatile or memory non-volatile memory. In one embodiment,
the binary code is stored in host memory 118. In one embodiment,
Set B includes the capability to operate at a high voltage (e.g.,
3.5V). In one embodiment, Set B does not include the capability to
operate with a second voltage (e.g., 1.2V), as was the case of Set
A.
If the binary code is "01", then control passes to step 1114. Step
1114 includes a determination that the one or more capability pads
has a third physical configuration. In one embodiment, the third
physical configuration is the relatively short capability pad
106a-3 that is away to the front edge 302 of the removable
integrated circuit card 104, as depicted in FIG. 3c.
Step 1116 includes establishing the capability set as Set C. Step
1116 may include storing the binary code in memory. The memory
could be volatile or memory non-volatile memory. In one embodiment,
the binary code is stored in host memory 118. In one embodiment,
Set C includes the capability to operate at a low voltage (e.g.,
2.5V). In one embodiment, Set C does not include the capability to
operate with a second voltage (e.g., 1.2V), as was the case of Set
A.
If the binary code is "11", then control passes to step 1118. Step
1118 includes a determination that there are not any capability
pads on the removable integrated circuit card 104. FIG. 3d depicts
an example of a removable integrated circuit card 104 without a
capability pad (note that there is not an interface pad at either
target location 114a, 114b).
Step 1120 includes establishing the capability set as Set D. Step
1120 may include storing the binary code in memory. The memory
could be volatile or memory non-volatile memory. In one embodiment,
the binary code is stored in host memory 118. In one embodiment,
Set D includes the capability to operate at a high voltage (e.g.,
3.3). Set D could also include capabilities such as the capability
to operate with a second voltage (e.g., 1.2V), which would be
provided to a different interface pad than the aforementioned high
voltage.
FIG. 12 depicts a flowchart of one embodiment a process 1200 of
operating a removable memory card based on a capability set of the
removable memory card. In one embodiment, process 1200 is performed
in combination with process 1100. However, process 1200 is not
limited to being performed in combination with process 1100. The
process 1200 will be discussed with reference to FIG. 8, but is not
limited thereto. In one embodiment, process 1200 is performed by
card operation 712. Process 1200 describes some example
capabilities for Set A, Set B, Set C, and Set D. The capability
sets are not limited to these examples. Process 1200 describes
further details of one embodiment of step 1010 of process 1000.
Process 1200 describes further details of one embodiment of step
208 of process 200.
Step 1202 includes accessing a capability set for the removable
integrated circuit card 104. In one embodiment, the binary code
that was stored in host memory 118 in process 1100 is accessed. The
binary code indicates the capability set, as was discussed in
process 1100. For example, "00" may correspond to Set A, "10" may
correspond to Set B, "01" may correspond to Set C, and "11" may
correspond to Set D. As was discussed in process 1100, the binary
code may have more or fewer than two bits.
Step 1204 includes a decision of which branch to take based on the
capability set. If the capability set is "Set A", then control
passes to step 1206. Step 1206 includes connecting the removable
integrated circuit card 104 to a 2.5V power supply. In one
embodiment, switch 714 is connected to the 2.5V power supply 718.
Step 1208 includes connecting the removable integrated circuit card
104 to a 1.2V power supply. In one embodiment, switch 804 is
connected to the 1.2V power supply 802. Step 1210 includes
communicating with the removable integrated circuit card 104 using
2.5V signals. This communication takes place over one or more
interface pads 106.
If the capability set is "Set B", then control passes to step 1212.
Step 1212 includes connecting the removable integrated circuit card
104 to a 3.3V power supply. In one embodiment, switch 714 is
connected to the 3.3V power supply 716. Step 1214 includes
communicating with the removable integrated circuit card 104 using
3.3V signals. This communication takes place over one or more
interface pads 106.
If the capability set is "Set C", then control passes to step 1216.
Step 1216 includes connecting the removable integrated circuit card
104 to a 2.5V power supply. In one embodiment, switch 714 is
connected to the 2.5V power supply 718. Step 1218 includes
communicating with the removable integrated circuit card 104 using
2.5V signals. This communication takes place over one or more
interface pads 106.
If the capability set is "Set D", then control passes to step 1220.
Step 1220 includes connecting the removable integrated circuit card
104 to a 3.3V power supply. In one embodiment, switch 714 is
connected to the 3.3V power supply 716. Step 1222 includes
connecting the removable integrated circuit card 104 to a 1.2V
power supply. In one embodiment, switch 804 is connected to the
1.2V power supply 802. Step 1224 includes communicating with the
removable integrated circuit card 104 using 3.3V signals. This
communication takes place over one or more interface pads 106.
In some embodiments, in order to sense the physical condition of
the one or more capability pads 106a, the host device 102 provides
two or more voltages to the removable integrated circuit card 104.
The removable integrated circuit card 104 routes at least one of
the received voltages to at least one capability pad 106a in order
to indicate the capability set. An example of this was described
above in connection with FIGS. 5a-5d.
FIG. 13 depicts one embodiment of a system in which the host device
102 provides two voltages to the removable integrated circuit card
104, the removable integrated circuit card 104 routes one of the
received voltages to a capability pad 106a, and the host device
senses the voltage at the capability pad 106a. One target location
114a is depicted on the removable integrated circuit card 104, but
there could be more. The voltage detector 1302 is configured to
sense a voltage at sense contact 110a. The sense contact 110a
coincides with capability pad 106a. Switch 1304 is configured to
connect first voltage source 1306 to electrical contact 110d. Thus,
a voltage from first voltage source 1306 may be provided to
interface pad 106d. Switch 1308 is configured to connect second
voltage source 1310 to electrical contact 110c. Thus, a voltage
from second voltage source 1310 may be provided to interface pad
106c. First voltage source 1306 has a different magnitude that
second voltage source 1310. In one embodiment, first voltage source
1306 is a positive voltage and second voltage source 1310 is
ground. In some embodiments, first voltage source 1306 is referred
to as VD and second voltage source 1310 is referred to as Vs. The
control circuit 120 in the removable integrated circuit card 104
has voltage routing 1312 that is configured to route one of the
received voltages to capability pad 106a. In another embodiment,
the removable integrated circuit card 104 has two capability pads
106a, wherein the voltage routing 1312 that is configured to route
one of the received voltages to the second capability pad 106a. The
removable integrated circuit card 104 could have three or more
capability pads 106a, wherein the voltage routing 1312 is
configured to route one of the received voltages to each of the
additional capability pads 106a.
FIG. 14 depicts a flowchart of one embodiment of a process 1400 of
determining a capability set based on voltages provided by a host
device 102. Process 1400 will be discussed with respect to FIG. 14,
which depicts one embodiment of host components. Process 1400 will
be discussed with respect to FIGS. 5a-5d, but is not limited
thereto. Process 1400 is one embodiment of step 204 in process
200.
Step 1402 includes the host device 102 providing a first voltage to
a first interface pad 106d of the removable integrated circuit card
104. For example, with reference to FIGS. 5a-5d, the host device
provides V to interface pad 106d. With respect to FIG. 13, switch
1304 is closed to connect first voltage source 1306 to electrical
contact 110d.
Step 1404 includes the host device 102 providing a second voltage
to a second interface pad 106c of the removable integrated circuit
card 104. For example, with reference to FIGS. 5a-5d, the host
device provides G to interface pad 106c. With respect to FIG. 13,
switch 1308 is closed to connect second voltage source 1310 to
electrical contact 110c.
Step 1406 includes the removable integrated circuit card 104
providing at least one of the voltages to at least one capability
pad 106a. With respect to FIG. 14, the voltage routing may be used
to route one of the voltages at either interface pad 106c or 106d
to capability pad 106a. FIGS. 5a-5d depict four possibilities. In
one embodiment, only one capability pad 106a is used. In one
embodiment, more than two capability pads 106a are used.
Step 1408 includes the host device 102 sensing a voltage at the
respective one or more capability pads 106a. FIG. 13 depicts
voltage detector 1302 that may be used to sense the voltage at a
capability pad. The voltage detector 1302 may include a comparator
that has one input that receives a reference voltage and another
input that is connected to sense contact 110a. The output of
voltage detector 1302 may be provided to a capability determination
unit, such as has been described with respect to FIGS. 6 and 7.
A first aspect of the disclosed technology includes an apparatus,
comprising a card connector and one or more control circuits. The
card connector is configured to receive a removable integrated
circuit card having interface pads. The interface pads include one
or more capability pads. The one or more control circuits are
configured to sense a physical condition of the one or more
capability pads when the removable integrated circuit card is in
the card connector. The one or more control circuits are configured
to determine a capability set of the removable integrated circuit
card based on the physical condition of the one or more capability
pads. The one or more control circuits are configured to operate
the removable integrated circuit card based on the capability
set.
In a second aspect of the disclosed technology in furtherance of
the first aspect, the physical condition comprises a physical
configuration of the one or more capability pads. The one or more
control circuits are configured to determine the capability set of
the removable integrated circuit card based on the physical
configuration of the one or more capability pads.
In a third aspect of the disclosed technology in furtherance of
either of the first or second aspects, the one or more control
circuits are further configured to provide a voltage to a first end
of a resistive element that has a second end connected to a target
location on the removable integrated circuit card. The one or more
control circuits are further configured to compare a magnitude of a
voltage at the target location with a reference voltage in order to
sense the physical condition of the one or more capability
pads.
In a fourth aspect of the disclosed technology in furtherance of
any of the first to third aspects, the one or more control circuits
are further configured to: provide a voltage to a first end of a
resistive element that has a second end connected to a first target
location on the removable integrated circuit card, connect a second
target location on the removable integrated circuit card to ground
while the voltage is provided to the first end of the resistive
element, and compare a magnitude of a voltage at the first target
location with a reference voltage in order to sense the physical
condition of the one or more capability pads.
In a fifth aspect of the disclosed technology in furtherance of any
of the first to fourth aspects, to sense the physical condition of
the one or more capability pads the one or more control circuits
are further configured as follows. The one or more control circuits
are further configured to provide a first voltage to a first end of
a first resistive element that has a second end connected to a
first target location on the removable integrated circuit card. The
one or more control circuits are further configured to provide a
second voltage to a first end of a second resistive element that
has a second end connected to a second target location on the
removable integrated circuit card. The second voltage is provided
to the first end of the second resistive element while the first
voltage is provided to the first end of the first resistive
element. The one or more control circuits are further configured to
compare a magnitude of a third voltage at the first target location
with a first reference voltage. The one or more control circuits
are further configured to compare a magnitude of a fourth voltage
at the second target location with a second reference voltage.
In a sixth aspect of the disclosed technology in furtherance of any
of the first to fifth aspects, the apparatus further comprises a
first voltage source configured to provide a first voltage to a
first interface pad of the interface pads. The apparatus further
comprises a second voltage source configured to provide a second
voltage to a second interface pad of the interface pads. The first
voltage is greater than the second voltage. The one or more control
circuits are further configured to sense a voltage at each of the
one or more capability pads when the first voltage is provided to
the first interface pad and the second voltage is provided to the
second interface pad.
In a seventh aspect of the disclosed technology in furtherance of
any of the first to sixth aspects, the one or more control circuits
are further configured to sense an absence of a capability pad at
one or more target locations on the removable integrated circuit
card. The one or more control circuits are further configured to
determine the capability set of the removable integrated circuit
card based on the absence of a capability pad at the one or more
target locations on the removable integrated circuit card.
In an eighth aspect of the disclosed technology in furtherance of
any of the first to seventh aspects, the one or more control
circuits are further configured to sense the physical condition of
the one or more capability pads while the removable integrated
circuit card is powered off.
In a ninth aspect of the disclosed technology in furtherance of any
of the first to eighth aspects, the one or more control circuits
are further configured to sense the physical condition of the one
or more capability pads prior to the apparatus providing any
commands to the removable integrated circuit card.
In a tenth aspect of the disclosed technology in furtherance of any
of the first to ninth aspects, the removable integrated circuit
card comprises a removable memory card. The removable memory card
comprises non-volatile memory. The capability set comprises a
voltage level at which the removable memory card is capable of
operating.
In an eleventh aspect of the disclosed technology in furtherance of
any of the first to tenth aspects, the one or more control circuits
are configured to operate the removable integrated circuit card
based on the capability set comprises the one or more control
circuits configured to use at least one of the capability pads
while operating the removable integrated circuit card based on the
capability set.
In one embodiment, the apparatus includes a host device 102. The
apparatus could be, but is not limited to, a desktop computer,
laptop computer, a notepad computer, a digital camera, a cellular
telephone, a personal digital assistant, a portable media player,
an electronic keyboard, or a video game console.
One embodiment of the disclosed technology includes a method of
operating a removable memory card. The method comprises providing a
voltage to a first end of a resistive element in a host device. A
second end of the resistive element is connected to a target
location on a removable memory card in a card connector of the host
device. The method comprises comparing a magnitude of a voltage at
the target location with a reference voltage, and detecting a
physical configuration of one or more capability pads of the
removable memory card based on the comparison. The method comprises
determining a capability set of the removable memory card based on
the physical configuration of the one or more capability pads, and
operating the removable memory card based on the capability set
while the removable memory card is in the card connector of the
host device.
One embodiment of the disclosed technology includes an apparatus
comprising means for sensing a physical configuration of one or
more capability pads of a removable memory card that is in a card
connector of a host device. The apparatus also includes means for
determining a capability set of the removable memory card based on
the physical configuration of the one or more capability pads. The
apparatus also include means for operating the removable memory
card based on the capability set.
In one embodiment, the means for sensing a physical configuration
of one or more capability pads of a removable memory card that is
in a card connector of a host device comprises one or more of
sensing circuit 112, sense contacts 110a, 110b, voltage detector
608, 708a, 708b, a comparator, a resistive element 604, 704, a
resistor, a transistor, host processor 116, a PGA, an FPGA, and/or
an ASIC. In one embodiment, the means for sensing a physical
configuration of one or more capability pads of a removable memory
card that is in a card connector of a host device performs steps
1002-1006 of process 1000.
In one embodiment, the means for determining a capability set of
the removable memory card based on the physical configuration of
the one or more capability pads comprises one or more of capability
determination 610, capability determination 710, host processor
116, a PGA, an FPGA, and/or an ASIC. In one embodiment, the means
for determining a capability set of the removable memory card based
on the physical configuration of the one or more capability pads
performs process 1100.
In one embodiment, the means for operating the removable memory
card based on the capability set comprises one or more of
capability determination 610, capability determination 710, host
processor 116, a PGA, an FPGA, and/or an ASIC. In one embodiment,
the means for operating the removable memory card based on the
capability set performs process 1200.
In one embodiment, the means for sensing the physical configuration
of the one or more capability pads comprises sensing means for
coupling a voltage to one or more target locations on the removable
memory card, the sensing means further for sensing a resultant
voltage at each of the one or more target locations. In one
embodiment, sensing means for coupling a voltage to one or more
target locations on the removable memory card, the sensing means
further for sensing a resultant voltage at each of the one or more
target locations comprises one or more of sensing circuit 112,
sense contacts 110a, 110b, voltage detector 608, 708a, 708b, a
comparator, a resistive element 604, 704, a transistor, and a
resistor.
In one embodiment, the means for determining the capability set of
the removable memory card based on the physical configuration of
the one or more capability pads comprises means for determining the
capability set based on the resultant voltage at each of the one or
more target locations. In one embodiment, the means for determining
the capability set based on the resultant voltage at each of the
one or more target locations comprises one or more of capability
determination 610, capability determination 710, host processor
116, a PGA, an FPGA, and/or an ASIC. In one embodiment, the means
for determining the capability set based on the resultant voltage
at each of the one or more target locations performs process
1100.
One embodiment of the disclosed technology includes a removable
memory card. A removable memory card comprises one or more control
circuits configured to operate the removable memory card in
accordance with a capability set. The plurality of interface pads
are coupled to the one or more control circuits. The plurality of
interface pads are configured to be received by a card connector of
a host device. The plurality of interface pads comprise one or more
capability pads that are configured to indicate the capability set
based on a physical condition of the one or more capability pads
when the plurality of interface pads are received by the card
connector.
In a further embodiment of the removable memory card, the one or
more capability pads are configured to indicate the capability set
based on a physical configuration of the one or more capability
pads. In one embodiment, the physical configuration is a size of a
capability pad. In one embodiment, the physical configuration is a
length of a capability pad. In one embodiment, the physical
configuration is a number of capability pads.
In a further embodiment of the removable memory card, a first of
the interface pads is configured to receive a high voltage, a
second of the interface pads is configured to receive a low
voltage, and the one or more control circuits are configured to
provide at least one of the high voltage or the low voltage to
respective ones of the one or more capability pads to indicate the
capability set of the memory card.
In a further embodiment of the removable memory card, the one or
more control circuits are configured to use at least one of the
capability pads during operation of the removable memory card under
the capability set. In one embodiment, the one or more control
circuits are configured to use at least one of the capability pads
during operation of the removable memory card to receive a power
supply voltage. In one embodiment, the one or more control circuits
are configured to use at least one of the capability pads during
operation of the removable memory card for data communication with
the host device. In one embodiment, the one or more control
circuits are configured to use at least one of the capability pads
during operation of the removable memory card to receive a clock
signal from the host device.
The foregoing detailed description of the invention has been
presented for purposes of illustration and description. It is not
intended to be exhaustive or to limit the invention to the precise
form disclosed. Many modifications and variations are possible in
light of the above teaching. The described embodiments were chosen
in order to best explain the principles of the invention and its
practical application to thereby enable others skilled in the art
to best utilize the invention in various embodiments and with
various modifications as are suited to the particular use
contemplated. It is intended that the scope of the invention be
defined by the claims appended hereto.
* * * * *